America is reaching a "tipping point" in marijuana legalization that could eventually spur a national change by the next midterm election, pot investor Paul Rosen told CNBC Wednesday.

"There's sort of an irrevocable momentum towards sensible cannabis reform, which ultimately should lead towards a harmonization of federal and state laws," the founder of Breakwater Venture Capital said on "Power Lunch."

Michigan, where voters passed medical marijuana laws 10 years ago, is the latest to join the circle of 10 states and Washington, D.C., that have legalized weed for recreational use. Voters in Utah and Missouri also relaxed their laws to allow medical marijuana in Tuesday's midterm election.

"Individually, it's just another data point that suggests that the desire for sensible cannabis reform at a state and a citizen level is enhancing in every election season," said Rosen, former CEO of PharmaCan Capital, which later became Cronos Group.

However, voters in North Dakota, where medical marijuana is legal, declined legalizing the drug for recreational use Tuesday. And weed is still illegal federally, which presents a host of other challenges for the budding pot industry.

But cannabis stocks are rising on hopes that more help for further reform could be on the way in the near future.